Manually-operated ultra-high-vacuum water-cooled slit mechanism for the U13U wiggler/undulator spectroscopy branch line at the National Synchrotron Light Source

The authors describe a manually-operated ultra-high-vacuum (UHV) water-cooled slit mechanism. The design, which is based on the use of rigid parallelograms, provides a continuously adjustable bilateral slit opening. The entire mechanism is mounted on an eight-inch Conflat flange with two bellows for cooling water tubes and a linear feedthrough to control the size of the slit opening

Sensitization tests in carbon dioxide of CR-39 track etched neutron dosemeter

A CO2 pre-etching treatment of a CR-39 neutron dosemeter is thoroughly analyzed in this work, in order to identify the optimal conditions to obtain the maximum neutron sensitivity

Optimization of the sensitization of CR-39 etched track neutron dosemeters with carbon dioxide

Although etched-track detectors, in particular the polyallyl-diglycol carbonate (PADC), i.e. CR-39, are the most popular among passive neutron personal dosimeters (d’Errico and Bos, 2004), there are still challenges to be addressed, such as counting automatically the small recoil proton tracks. A pre-etching treatment with CO2 under pressure is a technique used to enhance the track size and readability, and had been confirmed in various reports (Csige, 1997; Fujii et al., 1995; Yamauchi et al., 2009). However, only a few investigated the response for fast neutrons (Hulber and Selmeczi, 2005; Shimada et al., 2011), and not completely. Therefore, the present study is attempted to confirm the sensitization effect once again and thoroughly analyse the process, in order to identify the optimal conditions for maximum neutron sensitivity. For that, CR-39 plates were irradiated with 241AmBe neutron source, and tested under different treatment time (1 – 5 days) and carbon dioxide pressure (0.1 – 0.5 MPa), which are the two parameters that characterize the pre-etching treatment. An increase, up to X %, of track density was seen

Influence of sample preparation optimization on the accuracy of dose assessment of an automatic non-fluorescent MN scoring system

Purpose: Automatizing the scoring of the cytokinesis-blocked micronucleus assay spares a lot of valuable time. The dose-effect relationship can be applied reliably for dose estimation if the quality of the slides is the same from the perspective of the used image processing algorithm. This aspect brings in additional requirements against the quality of the slides compared to the conventional visual scoring. Materials and methods: An add-in software was created to the non-fluorescent RS-MN automatic MN scoring system which is capable of measuring quantitatively the degree of typical anomalies. The image processing is less reliable when the presence of these anomalies is more frequent. The behavior of the designed sample quality parameters (SQPs) was tested on in vitro irradiated peripheral blood samples (0, 1, and 2 Gy) obtained from a healthy donor and also on samples from patients undergoing low dose-rate brachytherapy. Results: We examined 20 different SQPs and identified two that are independent and correlate significantly with the error of the fully automatic MN frequency. One is related to the size of the cells and the other reflects the homogeneity of the environment. An equation was established which presents a connection between the error of the auto MN frequency and the SQPs. By adding a fourth cleaning step to the conventional sample preparation and changing the pre-dripping temperature of the slide, the SQP can be modified, and consequently, the sample quality can be improved. The gain in accuracy is 54 ± 10 MN per 1000 binucleated cells, which corresponds to the effects of 0.5 Gy. Around the lowest limit of detection (<0.5 Gy), it means a 50–100% drop in the error of dose, which is significant. With sample quality harmonization, the positive predictive value was raised to 80–93% depending on the dose. Conclusions: With the technique described in this paper, the suitability for automated scoring of a micronucleus slide can be tested quantitatively and objectively. A method is presented with which in some cases the uncertainty of the assessed doses due to variance in sample quality can be decreased or if it is not possible its bias can be predicted. The proposed protocol leads to more reliable estimation of dose. The SQPs are designed in a way that they have the potential to be adapted to similar systems

Reply to Keller and Springborn: No doubt about invasion debt

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